Electron scattering by methane: elastic scattering and rotational excitation cross sections calculated with ab initio interaction potentials

Journal Article · Tue Feb 01 04:00:00 EST 1983 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1002/chin.198319041· OSTI ID:6523384

Abusalbi, N; Eades, R A; Nam, T; Thirumalai, D; Dixon, D A; Truhlar, D G; Dupuis, M

We calculate ab initio interaction potentials for electron-methane scattering and use them to perform converged scattering calculations for the electronically and vibrationally elastic rotational-state-to-rotational- state cross sections at 10 eV impact energy. The effective potential has static, local exchange, and polarization terms calculated from extended-basis-set Hartree--Fock wave functions for both unperturbed and polarized methane molecules. The polarization potential includes nonadiabatic effects in the semiclassical local kinetic energy approximation, and for comparison we also perform calculations based on the adiabatic polarization potentials. Five to 12 terms are retained in the angular expansion of the various parts of the interaction potential and the coupled channels calculations involved 41 total angular momenta, with 1--33 coupled channels for each. The resulting rotationally summed integral cross sections are in excellent agreement with recent experiments for scattering angles 40/sup 0/ and larger, but are larger than the experiment at small scattering angles. The rotationally inelastic cross sections for the full potential are smaller than those for the adiabatic potential by about a factor of 2.

• Research Organization: Department of Chemistry and Chemical Physics Program, University of Minnesota, Minneapolis, Minnesota 55455
• OSTI ID: 6523384
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 78:3; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ALKANES
COLLISIONS
CROSS SECTIONS
ELASTIC SCATTERING
ELECTRON COLLISIONS
ELECTRON-MOLECULE COLLISIONS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXCITED STATES
HYDROCARBONS
METHANE
MOLECULE COLLISIONS
ORGANIC COMPOUNDS
POTENTIALS
ROTATIONAL STATES
SCATTERING